The Sinclair QL Forum

Most OSes switch to polling mode in those circumstances.

That doesn't fit for devices that can issue 1000+ interrupts per second. Why bottleneck them to when you feel like polling them?

Dave wrote:That doesn't fit for devices that can issue 1000+ interrupts per second. Why bottleneck them to when you feel like polling them?

Erm, this is exactly how most OSes deal with high bandwidth devices. You think your devices are fast, try 100G network interfaces.

Dave wrote: Mon Sep 01, 2025 7:03 pm Any chance to post a timing chart for the Q68 extension bus? HD/ED floppy interface seeks SMSQ/E DP8473V floppy driver remapping to extension bus and details for logic.

I can not just take a photo, since that timing chart does not exist. I haven't dealt with the bus timings in a decade, so researching and documenting them is more work than I currently would like to do. Sorry that I postponed and eventually forgot it. The mapping is documented in the Q68 manual though, and others had no problem with it.

Unfortunately I have little interest in a Q68 floppy controller, and I don't believe drivers will be written, so my motivation is not the best.

If you don't wish to post a picture of your QL sound card, okay. I don't understand what the Q68 bus timings have to do with that.

By the way, the "68K bandwidth theoretical best-case" table looks wrong to me. E.g. the 68060 bursts 16 Bytes in 5 clock cycles maximum.

Hi,

I do not see the point of of a disk interface on the Q68, since the the media : new HD Disks are not made in any quanities, with respect to ED Disks, I havd never seen them in any quantities.

So hardware would be interesting to look at, but why... at present I can use a 256 MB FAT partition on a SD Card which can hold Disk Images of HD, ED formats.

With regards to the Sound Card, I would like to see pictures of the card, which sounds excellent in the concept and design.

I would like to buy one.

No pic *yet* because there's other things on the same proto-board I don't want to preview yet. I've already let slip I have SATA working. Other parts just aren't ready for getting specific feedback on yet. There will be pics if/when it reaches a state where I have it released and available for sale, packed in boxes ready to ship. I might break this rule in future if I get into the habit of actually completing projects in the QL community again. I really don't even talk about things anymore until they're prototyped and at least the hardware is validated.

I now know from feedback what is needed, what is achievable and would be useful without breaking things, and how I can implement it for past and future hardware.

The floppy driver already exists in SGC 2.49 and SMSQ/E. This is the same DP8473V '765-compatible' floppy controller used on the (S)GC. It mostly works - I just can't get the timings right as there's no system clock to scale them against. PEEK and POKEing from BASIC isn't useful for testing that. The driver just needs editing to use the extension port addresses. I have to further decode the port because I don't want the floppy controller occupying more than its bytes, leaving room for other things later.

But that's a separate discussion.

Derek_Stewart wrote: Mon Sep 01, 2025 11:12 pm I do not see the point of of a disk interface on the Q68, since the the media : new HD Disks are not made in any quanities, with respect to ED Disks, I havd never seen them in any quantities.

So hardware would be interesting to look at, but why... at present I can use a 256 MB FAT partition on a SD Card which can hold Disk Images of HD, ED formats.

It allows people to chuck things on floppy. Floppies are fun. They're a handy way of sharing things with friends in person, without the challenges of swapping SD card images or setting up a QLnet. You can grab any old floppy in any old format and look at it very low level. Distribute old games on floppies. Etc. It's just a minor convenience for some and desirable to some and of no interest to others. The Q68 fitting completely within the width of a dual floppy unit makes for a few fun case ideas for an all in one desktop with a bit more mass and utility than a base Q68.

I have a couple thousand black HD floppy disks and several hundred ED floppies. I started collecting and refurbishing black faced drives a few years ago when I had none and Phoebus sent me a couple from Greece. I now have 'piles' of matching, refurbed, tested drives ready to go in systems. Mostly Sony, NEC, Matsushita in that order. I have some black ED drives, new old stock.

Dave wrote: Tue Sep 02, 2025 9:19 pm Floppies are fun.

Not at all. Sometimes I still have to use floppy on the Q60, and I hate it everytime. It's the most unreliable medium, practically all my old QL floppies have damaged files. Even my microdrives have aged better. Also floppies tend to be full everytime I need one more file, or files are too long to fit at all.

Dave wrote: Tue Sep 02, 2025 9:19 pm They're a handy way of sharing things with friends in person, without the challenges of swapping SD card images or setting up a QLnet.

Disagreed. We live in internet times, and a QXL.WIN file is easier to share that way, especially if executables are included. For local exchange, all native SD card interfaces (I'm aware of) support hot swapping and auto-detect card changes. So floppy has no advantage left, except that it can be formatted natively.